1. Field of the Invention
The invention relates to a peer-to-peer transmission for data streams. Such a transmission system is, for example, known from the book “Peer-to-Peer-Systems and Applications” authored by Ralf Steinmetz and Klaus Wehrle, Springer Publishing, 2005, ISBN 3-540-29192-X.
2. Present State of the Art
Peer-to-peer (P2P) systems are network architectures of higher level, consisting of computers having equal rights (Peers), which participate at a collective data transmission and may thereby undertake both receiving and transmitting tasks. The total behavior of the system results from the local interactions between the peers. No central coordination of the interactions between the peers and no central data basis exist. On the contrary, each individual peer merely stores a part of the data present in the entire system and provides the other peers with this part. All stored data are thus available in the entire system. No peer administrates the entire existing content of data.
An example for a known peer-to-peer (P2P) system having a collective of peers 10, 20, 30 and a peer-to-peer transmission mechanism 40 is shown in FIG. 1. A data stream is fed to a transmitting peer 10 via its data input 11 by another peer of the collective. A data partitioner 12 in the transmitting peer 10 logically and with regard to time divides the incoming data stream into different parts, which are buffered in a volatile memory 13 so that the individual parts may be transmitted, on different paths by means of the peer-to-peer transmission mechanism 40, to the receiving peers 20, 30 via connections 41. The peer-to-peer transmission mechanism 40 is a transmission mechanism in a collective of peers, in which the data is distributed from at least one point (transmitting peer) to at least a point (receiving peer) in a non-central manner, namely by forwarding it between receiving peers.
The parts of the subdivided data stream, received from the receiving peer 20 via the connection 41, are therein buffered in a volatile memory 21 and reassembled into a complete data stream, which is available at a data output 23. A semiconductor main memory may, for example, be provided as the volatile memory 21. Further, from the volatile memory 21, the buffered parts of the subdivided data stream may be forwarded to other receiving peers in the collective 30 via the connections 42 and the peer-to-peer mechanism 40, whereby the receiving peer 20 assumes the role of a submitting peer at least partially. The parts of the subdivided data stream, buffered by the volatile memory 21, are further copied into a persistent memory 22 of the receiving peer 20 in order to copy them back into the volatile memory 21 at a later point in time if necessary. A disc drive memory may, for example, be provided as the persistent memory 22. The copied-back parts of the subdivided data stream may in turn be forwarded from the volatile memory 21 to other receiving peers in the collective 30 via the connections 42 and the peer-to-peer transmission mechanism 40, whereby, in this case as well, the receiving peer 20 assumes the role of a transmitting peer at least partially.